Nondestructive Evaluation of Impact Damage in Thick Graphite/Epoxy laminates

Problem Statement
Impact results in damage well below the surface with very little visible damage at the point of contact. This damaged region is well-embedded below the surface. By ultrasonic C-scan using a time-gated measurement of echo amplitude, 451 planes were scanned for determing damage location. The first two images show layers that contain the damage. The lower figure shows the extent of the damage by removing the darker colors that masked the core of the damaged region. But yet embedded within this core is the largest amplitude which cannot be seen.

Visual Insight
With translucency the maximum amplitude embedded within the damage region can be seen in the final figure. Again we observe that with rotation allows us to locate the position of the largest amplitude.